Sheet feeding machine



April 17, 1951 H, BQBST 2,549,364

SHEET FEEDING MACHINE Filed Aug. 1, 1947 I 7 fkzzw 1905,51 I

Patentecl Apr. 17, 1951 UNITED, STATES P TENT OFFICE Section 1, Publie Law 690, August 8, 1946 Patent iipiies April 26', 1961 9 Claims. (01. 271- 62) This invention relates to machines for feeding sheets, blanks or the like of cardboard 'or similar relatively thick material, the machines being of the kind including means for separating and feeding the sheets one at a time from the top of a pile and means for supporting the pile and for raising the same progressively, in cooperation with a feeler engaging the topmost sheet, so as to maintain the top of the gradually decreasing pile at a substantially constant level.

With machines of this kind and in order to replenish the pile of sheets without stopping the separating and feeding operation, it is known to provide means for supporting the last few sheets of the pile while the platform on which the pile is normally supported and by which it has been progressivel raised is lowered to receive a new pile, the platform being then again raised until the top sheet of the new pile is in a position to support the remaining sheets of the previous pile.

In one such machine the platform, which is carriedon the upper end of a vertically movable slide bar, supports a comparatively thin drawplate of steel or other suitable material on which is arranged a pile of sheets or the like, drawplate-maintaining devices in the form of resiliently inwardly pressed rack elements being provided to engage pawl-shaped projections on the drawplate so as to retain the latter in its elevated position when the platform is lowered to receive a fresh supply of sheets. When the platform, with the new pile of sheets thereon, has been raised to a position where the topmost sheet of the new pile contacts with or lies immediately below the drawplate supporting the remaining sheets of the previous pile, said latter drawplate is withdrawn and is inserted between the upper surface of the platform and thelowermost sheet of the new pile, the remaining sheets of the previous pile resting on the top of the new pile. The means for lowering the platform to receive a new pile of sheets and for again raising it to the desired level comprises a pluralit of chains each having one end secured to the platform and at the other acounterweight, the chains passing about sprockets rotatable as bymeans of a handwheel. Y

In another such machine, a set of primary elevatingchains, each having one endsecured to a set of lifting bars supporting the platform, is provided for raising the latter to maintain the u topmost sheet thereon at an approximately conant height, and there is further provided a set condary chains one end of each of which is connected to a set of adjustable lifting bars. The purpose of these adjustable lifting bars, which are operable independently of, and alternately with, the lifting bars carrying the platform, is to support a series of loose laths, which are initially placed 'on the platform beneath the pile of sheets, when it is desired to lower the platform to receive a new pile of sheets. The adjustable lifting bars are adapted to be engaged by the pars supporting the platform and thereby progressively raised so that they are in position to support the laths when the platform is lowered, at which time the secondary chains are actuated to produce continued upward movement of said adjustable lifting bars, together with the laths and the remaining sheets of the pile. The laths are removed when the platform supporting the nevv pil'e has been raised to a position where the topmost sheet thereon contacts the laths.

The present invention "has for its object a simple and novel arrangemeht whereby the supply of sheets can be periodically and readily replenished without interrupting the separation and feeding of the sheets.

In accordance with the invention there is provided a machine of the kind referred to comprising a plurality of endless elevators each having means for removably supporting in superposed spaced relationship platforms on each of which is carried a pile of sheets, and for supporting independently of said platforms a drawplate interposed between each platform and the pile of sheets thereomfs'aid drawplates being of a thickness considerably less than that of the platforms and suchthat they are able to support, independently of v the platforms, only a small proportion of the sheets forming each completed pile.

The platforms and drawplates may be supported by the elevators so that each drawplate rests over its entire area on a platform, or alternatively the supporting means may be such that at their ends the drawplates are spaced above the platforms, fiexingu'n'd'er the weight of the piles of sheets so that their centre portions rest on the platforms. As the platforms are removable from their supporting means and the elevators continue, on cooperation withrthe feeler, to raise the piles, each platform can be Withdrawn when the pile thereon has been sufficiently reduced to be supported by the inter-posed drawplate, and each subsequent pile built up by the operator to support theremaining sheets of the previous pile on removal of the drawplate, without interrupting the separating and feeding operation.

In order that the invention may be clearly understood and readily carried into effect the same will hereinafter be more fully described with reference to the accompanying drawings, in which:

Figure 1 is a rear perspective view of a portion of a sheet feeding machine showing the sheet supporting and elevating means of the invention;

Figure 2 is a detail view showing one of the chain links for supporting the platform and drawplate;

Figures 3, 4 and 5 are detail views illustrating diagrammatically the function and operation of the drawplate; I

Figure 6 is a detail sectional view on line VI-VI of Figure 'I showing a preferred embodiment of drawplate and diagrammatically illustrating its method of use; and

Figure 7 is a plan view of a part of the drawplate shown in Figure 6.

Like reference denote like parts in the several figures.

Referring firstly to Figure l, the machine, as shown, comprises a pair of spaced frame members I each of which supports a shaft carrying chain or sprocket wheels about which pass and are thereby driven four endless chains, only three of said chains, designated by the numerals 2, 3 and 4, being shown. The chains are formed, as will later be described, to support between them superposed platforms on each of which is carried a pile of sheets or blanks of, for example, cardboard. Two such platforms 5, 6 are shown in Figure 1, the upper platform being in the operative or working position in which the sheets are individually removed for transfer to another part of the machine.

The means for removing the sheets individually from the pile T on the uppermost platform comprises a suction member 9, by which the top sheet is separated from the pile, and two further suction members If] by which said sheet is removed from the pile in the direction of the arrow H. Located rearwardly of the member 9 is a feeler member l2 the lower end of which is adapted to engage the topmost sheet of the pile adjacent the rear edge thereof and which in such position operates, in a manner which forms no part of the present invention, to control the upward movement of the superposed platform in dependence upon the progressively decreasing thickness of the pile of sheets I on the uppermost platform.

Each of the endless chains is provided at intervals throughout its length with links M formed with upper and lower lugs or projections I5, !6. The projections 15, as shown more clearly in Figure 2, serve to support the platforms by engagement with the opposite ends thereof, while the projections l6 engage and support the opposite ends of sheet metal drawplates [3. The projections i5, I6 are so arranged that the upper surfaces of the platforms are spaced a short distance from the lower faces of the drawplates E3. The latter, however, are of a thickness, e. g. 5 mm., which is insufficient to support a full pile of sheets, with the result that the drawplates, under the weight of the piles, flex or bend downwardly and, as shown inFigure 3, rest at their central portions on the associated platforms.

As the thickness of the uppermost pile l is progressively reduced by the removal of successive sheets therefrom, the drawplate l3 interposed between said pile and the platform 5 gradually resumes its normal fiat condition as shown in Figure 4, and when the weight of the considerably diminished pile is entirely sup-. ported by the drawplate, the platform 5 is withdrawn. When this has been done, the operator is able to add a further supply of sheets to the next lower pile 8, these further sheets being positioned on top of the already partially completed pile until the topmost sheet of said pile is immediately beneath or in contact with the lower face of the drawplate 13 supporting the pile 1. Thus the lowermost sheet of the upper pile l and the uppermost sheet of the next following pile 8 are then separated by a distance corresponding only to the thickness of the drawplate l3, as shown in Figure 5. The drawplate is then slid laterally with one hand from beneath the upper pile l which is retained in position of alignment with the other hand and this pile drops on to the pile 8.

It will be clear from the foregoing that the machine of this invention operates to raise the sheets or blanks continuously to the position from which they are successively removed without the need for reversing the elevating means by which the sheets are moved in order to replenish the supply. As each uppermost pile of sheets is reduced to such number that the associated drawplate !3 disengages from the corresponding platform and resumes its normal flat condition, the operator withdraws said platform, builds up the pile of sheets on the next following platform until only the drawplate supporting the remaining sheets of the upper pile separates the two piles,

and then withdraws this drawplate so that said remaining sheets drop on to the completed pile immediately below.

In order that the action of the feeler member If shall not be affected by the downward movement of the remaining sheets of the uppermost pile consequent upon the withdrawal of the drawplate !3, it is desirable that said drawplate be withdrawn slowly from beneath said sheets,

thereby maintaining contact between the feeler member and the topmost sheet. This slow withdrawal of the drawplate can, however, be avoided by constructing the drawplate as shown in Figures 6 and 7. In this arrangement a recess H is cut in the rear edge portion of the drawplate,

this recess, when the drawplate is in position be' neath a pile of sheets, allowing those portions of the sheets immediately below the feeler member [2 to be deformed as shown in Figure 6. As will be seen, those portions of the sheets of the uppermost pile l which cover the recess l! are bent downwardly so that the lowermost sheet engages the topmost sheet of the next following pile. When the drawplate is withdrawn only those parts of the sheets substantially corresponding to shape of the drawplate partake of the downward movement. Preferably the recess I! is of such dimensions as to provide for deformation of the sheets over an area which also allows the suction member 9 to maintain contact with the pile during withdrawal of the drawplate thus avoiding any disturbance of the correct operation of said member. This deformation will, of course, be gradual, increasing as the number of sheets in the pile decreases. The inclined sides of the recess I! provide for progressive dropping of those portions of the sheets in the vicinity of the suction member [9 when the drawplate is withdrawn.

To enable the machine to function continuous- V ly, the uppermost platform must be withdrawn 'while a few sheets still remain on the associated drawplate 13. To facilitatewithdrawal of the platform should the drawplate not entirely have disengaged therefrom, rollers I 8 may be provided on the platforms as shown in Figure 3, the running faces of said rollers projecting above the upper faces of the platforms. K

Instead of supporting the drawplates I 3 on the links I l as previously described, the drawplates may be supported over their entire area by the platforms and, when the latter are removed, hooks or the like on the elevating chains are caused to engage the edges of the drawplates. Alternatively short lengths of chain movable in the same direction and at the same speed as the elevating chains 2, 3, 4, could be secured to the drawplates to cause them to continue their upward movement on withdrawal of the platform. In a further modification the single link M for supporting the platform and the drawplate could be-replaced by, for example, two adjacent links, the upper link carrying the drawplate and the lower link supporting the platform.

What I claim is:

1. A sheet feeding machine comprising a plurality of endless elevators each having means for removably supporting in superposed spaced relationship platforms on each of which is carried a pile of sheets, and for removably supporting independently of said platforms a thin, flexible drawplate interposed between each platform and the pile of sheets thereon, said drawplates being each at least in part supported by a platform when fully loaded and of a thickness considerably less than that of the platforms and such that they are able to support, independently of the platforms, only a small proportion of the sheets forming each completed pile.

2. A sheet feeding'machine comprising a plurality of endless elevators each having means for removably supporting in superposed spaced relationship platforms on each of which is car-' ried a pile of sheets, and for removably supporting independently of said platforms a thin, flexible drawplate interposed between each platform and the pile of sheets thereon, the supporting means for the platforms and drawplates being so arranged that the portions of said drawplates engaging said supporting means are spaced above the platforms, and said drawplates being each at least in part supported by a platform when fully loaded and of a thickness considerably less than that of the platforms and such that they are able to support, independently of the platforms, only a small proportion of the sheets forming each completed pile.

3. A sheet feeding machine comprising a plurality of endless elevators each having means for removably supporting in superposed spaced relationship platforms on each of which is carried a pile of sheets, and for removably supporting independently of said platforms a thin, flexible drawplate interposed between each platform and the pile of sheets thereon, the supporting means for the platforms and drawplates being so arranged that said drawplates are completely supported by the platforms until the latter are withdrawn, and said drawplates being ch at least in part supported by a platform n, fully loaded and of a thickness consider- 3 less than that of the platforms and such 'they are able to support, independently of Platforms, only a small proportion of the ming each completed pile.

h et feeding machine comprising a plurality of endless elevators made of chains having links formed with projections for removably supporting in superposed spaced relationship platforms on each-of which is carried a pile of sheets, and for removablysupporting independently of said platforms a thin, flexible drawplate interposed between each platform and the pile of sheets thereon, said drawplates being each at least in part supported by a platform when fully loaded and of a thickness considerably less than that of the platforms and such that they are able to support, independently of the platforms, only a small proportion of the sheets forming.

each completed pile.

a 5. A sheet feeding machine comprising a plurality of endless elevators made of chains carrying links having each two projections intended to support removablyin superposed spaced rela tionship platforms on each of which is carried a pile of sheets, and for removably supporting independently of said platforms a thin, flexible drawplate interposed between each platform and the pile of sheets thereon, said drawplates being each at leastin part supported by a platform when fully loaded and of a thickness considerably less than that of the platforms and such that they are able to support, independently of the platforms, only a small proportion of the sheets forming each completed pile.

6. A sheet feeding machine comprising a plurality of endless elevators made of chains the links of which are provided with pairs of adjacent lugs, one of which is adapted to support removably a platform intended to carry a;pile of sheets, and the other a thin, flexible drawplate interposed in spaced relationship between each platform and the pile of sheets thereon, said drawplates being each at least in part supported by a platform when fully loaded and of a thickness considerably less than that of of the platforms and such that they are able to support, independently of the platforms, only a small proportion of the sheets forming each completed pile.

7. A sheet feeding machine comprising a plurality of endless elevators and hooks movable in the same direction and at the same speed as the elevators for removably supporting in superposed spaced relationship platforms on each of which is carried a pile of sheets, and for removably supporting independently of said platforms a thin, flexible drawplate interposed between each platform and the pile of sheets thereon, the supporting means for the platforms and drawplates being so arranged that the pertions of said drawplates engaging said supporting means are spaced above the platforms, said drawplates being each at least in part suppol ted by a platform when fully loaded and of a thickness considerably less than that of the platforms and such that they are able to support,

in superposed spaced relationship platforms on each of which is carried a pile of sheets, and for removably supporting independently of said platforms a thin, flexible drawplate interposed between each platform and the pile of sheets thereon, the supporting means for the plat-- forms and drawplates being so arranged that 7 8 the portions of said drawplates engaging said feeler and sheet-separating means being disortin means are spaced above the platposed adjacent the edge of the sheets remote WJWW/W we: 22/; my MW W mm we My zmz-wmglzli 10am pm /2 F I 41/; wig/m swat? 

